Effect of recalculations of air quality monitoring results on awareness on persistent organic pollutants concentrations Comparison of time series from POPs passive sampling

There are two generic methods of the persistent organic pollutants (POPs) sampling and assessment in the ambient air: first active air sampling working on principle of a pipeline circuit with adsorption filters, air pump and gasometer and secondly its passive alternative with the adsorption filters freely accessible to air in a metal shell without any mechanical parts. Both approaches have their own advantages and disadvantages and both are widely used in a number of monitoring programs. Since the outputs of the active samplers provide information on POPs concentration directly, there is an urgent need to recalculate the results of passive samplers, which is necessary for a comparison of the measurements, basement levels of pollution and propose environmental measures. Although there is an increasing number of calibration studies, no unique method was generally accepted yet. Several recalculation approaches derived both from empirical calibration studies and theoretical physical nature of the sampling process were used to obtain fully comparable data. The paper deals with 10-years-long time series of a concurrent passive and active POPs monitoring conducted at the Kosetice observatory (Czech Republic). Adapted causality testing of explained variation proportion between the active and passive sampling measurements is presented within the paper. This method is demonstrated on five sets of recalculated series with unified periods to estimate effects of the recalculation methods to resulting time series. As a result, there is a proposal how to select the most suitable approach for the recalculation.